This invention concerns in-ground swimming pools and particular methods of construction.
There are many methods for constructing in-ground pools, just as there are many types of pools themselves. Pools can be constructed of poured-in-place concrete, sprayed concrete, gunite or other such materials, or even of block and mortar. The walls and bottom of the pool are constructed to be water-tight or are lined with a water impervious liner. In terms of durability, a liner is not preferred. The methods of constructing water-tight, non-lined pools vary in difficulty and expense. For example, poured-in-place concrete pools require labor-intensive careful construction of the forms. Uncontrollable factors such as high ground water or untimely rainstorms can cause problems. The sprayed concrete or gunite methods expose workers to the dangers of using the spray gun, require large amounts of material and result in a weaker construction.
Another method of pool construction involves the use of pre-formed sectional panels to form the walls and/or bottom of the pool. This method has a number of advantages. The required excavations can be dug closer to the actual pool dimensions, as the panels are pre-formed and then placed in position. Pre-forming the panels allows mass production and the panels can be formed when weather conditions are optimum at the site or formed at other locations and transported to the site. Curing time for concrete panels is usually less than curing time for poured-in-place walls. Defective panels can be discarded and replaced without affecting the integrity of the entire pool.
The technique of using pre-formed sectional panels in pool construction is well-known. For example, Eichelman et al., in U.S. Pat. No. 1,908,332, teach the use of such panels. The panels are joined laterally by pouring concrete into vertical channels. Bennett, Jr., in U.S. Pat. No. 2,954,645, teaches pre-formed, reinforced panels which are joined to each other by bolts extending through flanges incorporated into each panel. Posnick, in U.S. Pat. No. 3,739,539, teaches the use of thermoplastic panels joined by a solvent weld formed in a removable clamp, followed by poured concrete.
The method of this invention, as well as the sectional panels themselves and the completed pool, are similar to the examples stated above. The invention is novel and distinct in the particular construction of the sectional panels and the method of joining these panels. The construction of the panels enables them to be joined by a simple metal welding operation, an improvement over the usual joining methods which require solvent or concrete to cure before construction of the pool can continue. In addition, no bolts or flanges are exposed to the damaging effects of corrosion, and the stresses between panels are evenly spread along the entire joint rather than focused at particular points. Construction is simplified since the method does not require exacting tolerances for fit and is readily adaptable to variation in shape, size or contour of the desired pool.